All rational numbers are integers? True/False

Iam trying to solve a linear equation for the shoe size of someone 84" tall taking into consideration example 1 is 69" tall with a shoe size of 9 and example 2 is 72 inches tall with a shoe size of 11. i understand that the equation should be y=mx+b and that on the graph the answer is (3,2) but i just don't understand how to create the equation to solve for 84-inches and 60-inches tall questions. after two days, i need .

The ratio of the measures of the three angles in a triangle is 2: 9: 4. find the measures of the angels

We just started the introduction into circles and i have no idea how to do this.